Luminescent and Color Wheel Synchronization for Projector Luminance
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Solution Overview
Problem
Conventional projectors using high-intensity discharge lamps or semiconductor laser light sources face issues with reduced luminance due to inefficient use of light emitted by luminescent materials, as excited light is often emitted in various directions and not all color segments can be utilized for image formation, leading to reduced luminance in projected images.
Innovation Solution
A light source unit comprising a luminescent wheel and a color wheel, where the luminescent wheel emits different wavelength ranges of light and the color wheel has specific transmission areas that allow for synchronized control of light emission, ensuring that light is effectively utilized across all segments, thereby enhancing luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a single color filter segment is used on the color wheel to emit a specific color, then color purity is improved, but all other segments cannot be used to emit light, resulting in reduced luminance
Solution Approach 1:
The color wheel is divided into multiple independent transmission area segments, each capable of transmitting specific wavelength ranges. This segmentation allows different segments to be selectively used for different color emission needs, enabling all segments to contribute to light output rather than leaving most segments unused.
Solution Approach 2:
Each transmission area segment on the color wheel is designed to transmit multiple wavelength ranges simultaneously (e.g., transmitting both blue-green light and red light through different spectral regions). This multi-functionality allows a single segment to serve multiple color emission purposes, increasing overall luminance while maintaining color versatility.
2Use of energy by moving object
If luminescent materials are excited by spotlight, then light emission is achieved, but the excited light is emitted in various directions causing loss of light that does not enter the integrator
Solution Approach 1:
An integrator is introduced as an intermediary optical component between the luminescent wheel and the projection optical system. The integrator collects luminous light emitted in various directions from the luminescent materials and redirects it into a unified beam path, enabling light that would otherwise be lost to contribute to the projected image.
Solution Approach 2:
The system transitions from direct directional light emission to multi-directional emission followed by optical integration. By allowing luminescent materials to emit light in various directions and then using the integrator to collect and redirect this light, the system effectively utilizes light from all spatial directions rather than requiring precise directional emission.
3Adaptability or versatility
If the number of colors for image formation is changed depending on projection mode, then adaptability is improved, but not all color filter segments can be used, resulting in reduced luminance
Solution Approach 1:
The control unit dynamically adjusts which transmission area segments on the color wheel are activated based on the selected projection mode. For example, in three-color mode, segments transmitting blue-green light, yellow-green light, and red light are activated; in two-color mode, only the necessary segments are activated. This dynamic adaptation ensures optimal luminance for each mode while maintaining flexibility.
Solution Approach 2:
The system changes operational parameters by selectively activating different combinations of transmission area segments on the color wheel according to projection mode requirements. This parameter adjustment allows the system to optimize both color emission capability and luminance output for each specific projection mode without wasting potential light sources.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution allows for reduced risk of luminance reduction in projected images by optimizing the use of light across all color segments, improving color reproduction and maintaining image quality across different projection modes.
Implementation Method 1
a luminescent wheel having a plurality of segments that receive light emitted from the light source to emit different wavelength ranges of light
Implementation Method 2
a color wheel separate from the luminescent wheel that has a first transmission area that transmits light, in visible light, that exists in a certain range of wavelengths and a second transmission area that transmits light that exists in a range of wavelengths
Data Source
AI summary
A projector includes alight source unit including a light source, a luminescent wheel having light source segments receiving light from the light source to emit different wavelength ranges of light, a color wheel separate from the luminescent wheel that has a first transmission area transmitting light, in visible light, existing in a certain range of wavelengths and a second transmission area transmitting light existing in a range of wavelengths broader than that of the light transmitted through the first transmission area and on to which the different wavelength ranges of light from the luminescent wheel are shone, and a control module controlling not only the luminescent wheel and the color wheel so that they are synchronized with each other but also the light source so that the light emitted from the light source is sequentially shone on to the light source segments.